The first is a way to make spoofing ( "falsify direction"). Is that as we all know many browser to put eg

A (at) domain (dot) com [email concealed]

This attempt to connect to the domain after the @ user and use the first word or letters that we have, this is not today because it is obvious that the first two are together and the second most of the browser asks for permission to such action. What's going on safari in this technique that makes it possible to do this not just to you and asks permission to enter site, the second is that there is some character who safari interprets as "invisible" by creating a link with that of user domain fake followed by a large number of characters "invisible" and lastly with the @ domain to enter this will lead to falsification of the site.

Another flaw is that the safari when writing on the same page with a "document.write" with an infinite while this may result in the browser is broken, causing the following fall

Access violation when writing to [0FDFFFEE]

Finally there is a certain character that causes safari break when it comes to making a link to "file: / /" this creates the following as a result fails